Reinforced fusible element

ABSTRACT

A REINFORCED FUSIBLE ELEMENT USEFUL IN FIRE EXTINGUISHING SPRINKLERS, FUSIBLE LINKS ON FIRE DOORS AND THE LIKE IS DISCLOSED WHEREIN THE FUSIBLE MATERIAL USUALLY SOLDER OF A LEAD ALLOY OR THE LIKE IS PROVIDED WITH REINFORCING MEANS FOR STABILIZING ITS SIZE AND SHAPE BY ACTING TO PREVENT COLD FLOW OF THE ALLOY AS A RESULT OF COMPRESSIVE OR TENSION FORCES THEREAGAINST. SPECIFICALLY A FUSIBLE ELEMENT MAY BE PROVIDED WITH REINFORCING FIBERS OF SUITABLE MATERIALS INCLUDING NATURAL FIBERS, SYNTHETIC FIBERS AND METAL FIBERS OR FINE STRANDS MAY BE MIXED INTO THE ALLOY SO AS TO BE DISPOSED CONTINUOUSLY THERETHROUGH AND STILL ANOTHER VERSION ENCLOSES A SECTION OF FUSIBLE MATERIAL IN A WOVEN JACKET ENGAGING THE SURFACE OF THE FUSIBLE MATERIAL THAT WOULD ORDINARILY EXPAND WHEN THE SAME IS SUBJECTED TO COMPRESSIVE FORCES, ETC.

Sept. 20, 1971 w. E. AULT 3,605,902

REINFORCED FUsIBLE ELEMENT Filed March 11, 1969 swam/lac Wayne E. Au/i-United States Patent Ofice Patented Sept. 20, 1971 3,605,902 REINFORCEDFUSIBLE ELEMENT Wayne E. Ault, Aurora, Ohio, assignor to A-T-O Inc.,Cleveland, Ohio Filed Mar. 11, 1969, Ser. No. 806,123 Int. Cl. A62c37/30 U.S. Cl. 169-42 1 Claim ABSTRACT OF THE DISCLOSURE A reinforcedfusible element useful in fire extinguishing sprinklers, fusible linkson fire doors and the like is disclosed wherein the fusible materialusually solder of a lead alloy or the like is provided with reinforcingmeans for stabilizing its size and shape by acting to prevent cold flowof the alloy as a result of compressive or tension forces thereagainst.Specifically a fusible element may be provided with reinforcing fibersof suitable materials including natural fibers, synthetic fibers andmetal fibers or fine strands may be mixed into the alloy so as to bedisposed continuously therethrough and still another version encloses asection of fusible material in a woven jacket engaging the surface areaof the fusible material that would ordinarily expand when the same issubjected to compressive forces, etc.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates to fusible elements of the type normally employed to hold otherdevices in predetermined relation pending attainment of a predeterminedtemperature upon which the other devices are to be released by fusing,that is softening of the fusible element.

(2) Description of the prior art Prior fusible elements have generallyconsisted of appropriately shaped units of a desirable fusible alloy,the fusing or softening temperature of which may be readilypredetermined. Such elements are generally in compression in a deviceusing the same such as a fire extinguishing sprinkler head wherein thelevers holding a cap on a discharge orifice are in turn held in desiredposition by the physical presence of the fusible element and so arrangedthat alteration in shape of the fusible element permits the levers tomove to a position opening the cap on the discharge orifice.

The present invention insures the retention of the desired physicalshape of the fusible element and precludes accidental operation due tocold flow of the fusible element or other alterations in its shape dueto causes other than those responsive to temperature at a desireddegree.

SUMMARY OF THE INVENTION A fusible element comprises a pellet likeportion of a metallic alloy such as for example an alloy which will fuseat 165 F. and consists of 30.51% lead, 24.45% tin, 41.22% bismuth and3.82% cadmium.

Those skilled in the art will recognize that the percentages of thematerials will vary depending upon the temperature at which the fusibleelement is to become operable.

The ability of fusible alloys such as the above example to withstandcompression without cold flow of the alloy is limited and the presentinvention provides means for insuring against such cold flow and therebymaintaining the physical shape of the fusible alloy as desired until thefusing temperature is reached. This is made possible by the addition offibers of bondable material throughout the fusible element and/or thejacketing of the fusible element in a woven flexible non-stretchablesleeve.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a fireextinguishing sprinkler showing a fusible element holding the mechanicallevers thereof in fixed orifice closing position.

FIG. 2 is a greatly enlarged side elevation of a fusible element havinga girdle thereabout.

FIG. 3 is an end view of the fusible element and girdle of FIG. 2.

FIG. 4 is a cross section on a greatly enlarged scale of a fusibleelement incorporating suitable fibers disposed throughout and bonded tothe alloy of the fusible element.

FIG. 5 is a perspective view on a greatly enlarged scale showing afusible element having a loosely woven flexible but non-stretchablejacket thereabout.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 of the drawing atypical environmental use of a fusible element may be seen to comprise afire extinguishing sprinkler which device includes a frame 10 a threadedbase 11 defining a passageway normally closed by a cap 12. A deflector13 is ai'fixed to the frame 10 in oppositely disposed relation to thecap 12 as will be understood by those skilled in the art. A compressionpin 14 positioned centrally through the upper portion 15 of the frame 10engages a plurality of levers 16, 17 and 18 respectively with the levers18 being held in spaced apart relation by a fusible element 19.

The exterior configuration of the oppositely disposed spaced apartlevers 18 is such that they cannot move through an opening 20 in thelever 16 until the fusible element 19 fuses so as to change shape andpermit the lovers 18 to move toward one another sufiiciently that theirconfigurations will clear the opening 20 whereupon the levers 16, 17 and18 fall free and permit the cap 12 to open the discharge orifice in thesprinkler.

In the prior art constructions the fusible element 19 is simply formedof a metal alloy that would fuse at a desired predetermined temperature.For example, these are conventionally 212, 286 and 360 F. In practicalexperience it has been found that when compression is constantlymaintained on a fusible element it tends to alter its shape by reason ofcold flow of material and sometimes to the point where accidentaloperation of the device controlled thereby results.

In order to utilize an inexpensive easily assmbled mechanical leverarrangement in a fire extinguishing sprinkler such as that shown in FIG.1 of the drawings, it is necessary to place the fusible element undersome degree of compression. By utilizing the invention disclosed hereinthe modified fusible element becomes capable of withstanding thecompressive forces applied thereto without altering the shape and yet isfully responsive in operation to a fusing temperature.

In FIG. 2 of the drawings a fusible element 21 of solid cylindricalshape is shown in side elevation with a band like girdle 22 positionedabout the middle portion thereof. The fusible element 21 is formed of afusible alloy such as that hereinbefore described and the band likegirdle 22 is formed of a harder metal such as brass which issufiiciently hard so as to Withstand any tendency of the fusible element21 to enlarge radially.

In FIG. 3 of the drawings an end view of the fusible element 21 may beseen and it will be observed that the band like girdle 22 is annular andextends completely thereabout.

In FIG. 4 of the drawings a fusible element 23 is illustrated which is asolid cylindrical shape of fusible alloy such as hereinbefore describedand incorporating a plurality of random length loose fibers 24distributed throughout. The fibers may be natural fibers, syntheticresin fibers, metallic fibers such as fine metal wire or metal shavingssuch as steel wool and the like and bondable to the fusible alloy so asto become an integral part thereof. The reinforcing action of the manyfibers within the body of the fusible element 22 reinforces the same andprevents its growth longitudinally or radially except at fusingtemperatures of the alloy.

In FIG. 5 of the drawings a perspective view of a fusible element 25 maybe seen and it is enclosed on its outer circular surface with a looselywoven jacket 26 of diagonally positioned woven fibers 27 so as to form aflexible but non-stretchable jacket thereabout. A prefered em bodimentof the form of the invention illustrated in FIG. 5 would comprise aloosely woven wire braid such as for example that used in hydraulic hoseconstructions and bondable to the surface of the fusible element so asto prevent relative movement therebetween while being capable ofcollapse upon fusing of said element.

It will thus be seen that a fusible element has been disclosed inseveral forms which is reinforced to prevent changes in its physicalshape at temperatures less than the fusing temperature of the alloy ofwhich the fusible element is formed, The fibers of FIG. 4 and theflexible, collapsible woven jacket of FIG. 5 prevent undesirable changeof shape of the fusible element and thereby meet the principal object ofthe invention.

Although but three embodiments of the present invention have beenillustrated and described it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention.

I claim:

1. A fusible element comprising a shaped section of a fusible alloyhaving means restraining cold flow of said alloy at temperatures lessthan the fusing temperature of said alloy, said means consisting of anon-stretchable loosely woven jacket enclosing said fusible elementcapable of collapsing upon fusing of said fusible element.

References Cited UNITED STATES PATENTS 1,362,236 12/1920 Delaney 169-382,004,833 6/1935 Rowley 16938 2,502,754 4/1950 Rowley 169-38 3,053,7139/1962 Juras 161-170 3,336,984 8/ 1967 Macartney 16938 3,282,658 11/1966Wainer 29-1835 3,303,006 2/ 1967 Morley 29-183.5X

M. HENSON WOOD, JR., Primary Examiner M. Y. MAR, Assistant Examiner US.Cl. X.R.

